build: add option for build profiling with clang -ftime-trace #3927

Job	Run time
Ubuntu Debug gcc7/C++17 llvm9 py3.7 oiio2.3 exr2.4 sse4 exr2.4	24m 32s
VFX2023 gcc11/C++17 llvm15 py3.10 oiio-rel avx2	17m 42s
Ubuntu gcc10/C++17 llvm10 oiio-2.5 avx2	7m 42s
macos-13 C++17 py3.11 MacOS-13 llvm17	20m 22s
VFX2021 gcc9/C++17 llvm11 py3.7 oiio2.4 sse4 batch-b8avx2	15m 31s
VFX2023 GPU Cuda11 gcc11/C++17 llvm15 py3.10 OIIO-main avx2	6m 8s
Ubuntu latest releases gcc11/C++17 llvm17 exr3.2 py3.10 avx2 batch-b16avx512	32m 46s
macos-14 C++17 py3.11 MacOS-14-ARM llvm17	9m 34s
VFX2022 gcc9/C++17 llvm13 py3.9 exr3.1 oiio-rel avx2	16m 54s
VFX2024 gcc11/C++17 llvm17 py3.11 boost1.82 oiio-rel avx2	22m 18s
Ubuntu bleeding edge gcc12/C++17 llvm17 oiio/ocio/exr/pybind-main py3.10 avx2 batch-b16avx512	13m 59s
VFX2022 clang12/C++17 llvm12 oiio-main py3.9 avx2 batch-avx512	17m 39s
VFX2024 sanitizers	29m 56s
Ubuntu clang14/C++17 llvm14 py3.8 avx2 batch-b16avx512	14m 22s
VFX2022 gcc9/C++17 llvm11 py3.9 exr3.1 oiio2.3 sse2 batch-b4sse2	17m 42s
VFX2023 abi check	10m 31s
Ubuntu clang-format	4m 51s
VFX2021 oldest everything gcc9/C++17 llvm9 py3.7 oiio2.3 no-simd	9m 35s
VFX2023 icc/C++17 llvm14 py3.9 oiio-main avx2	20m 7s
VFX2023 icx/C++17 llvm14 py3.9 oiio2.3 avx2	20m 25s
	5h 32m 36s

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